In current packaging technology bottles and other containers with bottle-like closures used generally for storing and selling liquids are of ever increasing importance. Generally two kinds of closures are used for bottles: in a simpler case the bottle is closed with a flanged cap which can be removed from the bottle only by the deformation of the cap. This is unsuitable for reclosing bottles, such as beer bottles. In other cases a thread is formed on the bottle neck and after the bottle is filled a threaded cap is screwed onto it. This screw cap often also has a collar portion that is pressed onto the bottle neck to demonstrate the untouched state of the bottle.
When opening the bottle, the cap becomes detached at the perforation from the collar that was pressed onto the bottle neck. Then the cap can be repeatedly unscrewed from, or respectively repeatedly screwed onto, the bottle.
Qualitative fluctuations in bottling technology, strength-parameters of the cap material, dimensional tolerances of the bottle and the quality of formation of perforation result in that the cap can be very often removed from the bottle only with difficulty. This causes problems even for persons with average physical strength not to mention the significant numbers of somewhat weaker juveniles and elderly people. As a consequence, many auxiliary devices became known for loosening caps that can be opened with difficulty or not at all. The common characteristic of such devices lies in that an increased turning torque can be exerted by pressing them generally onto the outer cylindrical surface of the cap and in the majority of cases the jammed cap can thus be screwed off the bottle.
A device similar to pliers is widely used in the catering trade, as well as in households for loosening the threaded caps of bottles. The curved clamping plates of this device can be pressed on the outer mantle of the cap by the aid of the grip of the device and the jammed cap can be screwed off the bottle neck when engaging it with the teeth.
The disadvantage of this device is that the plate-like clamping jaws cause an irreparable deformation or destruction of the cap and it becomes unsuitable for the repeated sealed closing of the bottle.
A device is disclosed in Hungarian Patent Specification No. 3428/84 which is suitable for undoing a threaded cap arranged on the neck of a bottle. The device is formed with a cavity having the shape of a rotary body and a geometry following that of the outer surface of a bottle cap. The cavity is open at one end and widens conically towards the open end. A conical thread is formed on the inner surface of the cavity. The direction of the pitch of the inner thread is always opposite to the direction of the pitch of the thread on the cap to be loosened. Accordingly, if the inner cavity of the device is placed onto the cap and the device is turned in the opening direction of the cap, the cap will be jammed into the inner cavity of the device, as a consequence, the cap can be easily loosened and screwed off from the bottle neck.
It is not absolutely necessary to remove the cap from the device after the bottle was opened and thus, when closing the bottle, the cap and the device together are screwed onto the bottle neck and the opener is left on the closed cap. Thereafter, by turning the device further, it can be easily removed from the cap and repeatedly installed onto the bottle neck. The device being-still screwed on the bottle can also be removed from the cap when loosening by turning the device upwards from the cap.
The main disadvantage of that device is that after it is removed from the cap that is screwed back onto the bottle, the cap gradually seals less and less as it is insufficiently pressed on the bottle. Repeated putting on and taking off the cap results in its deformation to such an extent that it becomes impossible to tighten it on the bottle neck by hand. In the course of repeated contact the device begins to slide loose on the cap, and then the bottle cannot be closed with proper sealing. The deformed cap and the collar remaining on the bottle neck also can hurt the user's fingers.
The object of the present invention is to provide a device, by the aid of which the differently sized threaded caps of bottles available in commerce can be loosened or screwed-off from the bottle neck and screwed back and tightened on the bottle neck repeatedly, and in such a manner that proper sealing can be achieved each time.